17223 JobTracker
16897 DataNode
17518 Jps
17451 TaskTracker
17129 SecondaryNameNode
8571 FsShell
Name node is not displaying
Seems like you are using the same user for starting all users, so If namenode is coming in the jps output, Probably namenode daemons might be got killed to not started properly. you may use the following command for ensuring namenode process running or not
ps aux | grep -i namenode
If not running you may need to format your namenode before starting hdfs service, stop all hdfs deamons using stop-dfs.sh script then format your namenode using the below command and start HDFS using the start-dfs.sh script.
hadoop namenode -format
Go through the below SO post if you are hitting the below situation.
Hadoop namenode needs to be formatted after every computer start
If you are looking to check all running JVMs on the host via 'jps',
you need to run the command as root. Otherwise, 'jps' will only show
JVMs running as your currently logged-in user.
Please see this link for more:
https://groups.google.com/a/cloudera.org/forum/#!topic/cdh-user/1dlxmB_GVuU
Should always check the logs.. :)
Related
I have Hadoop-3.1.3 and I can upload a file in hadoop pseudo distributed mode, also can display the contents of file.
but when I call jps command i am getting the following output
10912 DataNode
13072 ResourceManager
4480 NodeManager
6584 Jps
664 Namenode
I am unable to find secondary name node, is there a problem with any configuration or hadoop installation?
You're assuming that secondary namenode is started with psuedo-distributed?
If the basic commands work, then its fine.
You need to look at log files to know if something is broken, before asking elsewhere....
In general, I always suggest you use Apache Ambari to provision a Hadoop cluster
You can start the Secondary NameNode manually and observe the start up logs to see if there's anything wrong:
hdfs secondarynamenode
If there's no error, run jps again and hopefully you see SecondaryNameNode listed.
I'd suggest running hdfs --help and checking out all of the options, there's a lot of good stuff there.
Functionally, I was wondering whether there is a difference between starting a hadoop namenode with the command:
$HADOOP_HOME/sbin/hadoop-daemons.sh --config $HADOOP_CONF_DIR --script hdfs start datanode
and:
hdfs datanode
The first command gives me an error stating that the datanode cannot ssh into itself(this is running on a docker container), while the second command seems to run without that issue. The official hadoop documentation for this version, (2.9.1) doesn't mention "hdfs datanode" as a way to start a datanode.
I am running the following script to run all the hbase and hadoop processes in my hbase setup in virtual machine.
#!/bin/sh
start-dfs.sh
start-yarn.sh
start-hbase.sh
#hbase-daemon.sh start rest
hbase-daemon.sh start thriftr
Earlier all the processes used to run properly. But recently, I have force shutdown my virtual machine process without stopping the hbase and hadoop related processes. Then my datanode process stopped. Later I have formatted my name node process, using some suggestion on online. Now my name node comes properly but data node process does not come up. When I check the running java process (JPS) the datanode process is missing
4672 NodeManager
5474 ThriftServer
4098 NameNode
4408 SecondaryNameNode
5723 Jps
4555 ResourceManager
5372 HRegionServer
5246 HMaster
5182 HQuorumPeer
But earlier the DataNode process used to come properly. Is it because of formatting my namenode. Do I need to change any config data or someting also?
I am struggling to find out how to determine the status of different daemons in Hadoop. I know the status of only two daemons (namenode, jobtracker) since it is default in cloudera. How do I find the rest?
Use jps (need jdk installed) to see all the daemons.
Besides jps, you can scan the results given by below to check if processes are running-
ps -ef | grep hadoop
You can also use the following once the server is running
./hadoop dfsadmin -report
Another place to look at is the web interfaces of namenode and jobtracker for more details
I would like to see if the hdfs file system for Hadoop is working properly. I know that jps lists the daemons that are running, but I don't actually know which daemons to look for.
I ran the following commands:
$HADOOP_PREFIX/sbin/hadoop-daemon.sh start namenode
$HADOOP_PREFIX/sbin/hadoop-daemon.sh start datanode
$HADOOP_PREFIX/sbin/yarn-daemon.sh start resourcemanager
$HADOOP_PREFIX/sbin/yarn-daemon.sh start nodemanager
Only namenode, resourcemanager, and nodemanager appeared when I entered jps.
Which daemons are supposed to be running in order for hdfs/Hadoop to function? Also, what could you do to fix hdfs if it is not running?
Use any of the following approaches for to check your deamons status
JPS command would list all active deamons
the below is the most appropriate
hadoop dfsadmin -report
This would list down details of datanodes which is basically in a sense your HDFS
cat any file available in hdfs path.
So, I spent two weeks validating my setup (it was fine) , finally found this command:
sudo -u hdfs jps
Initially my simple JPS command was showing only one process, but Hadoop 2.6 under Ubuntu LTS 14.04 was up. I was using 'Sudo' to run the startup scripts.
Here is the startup that work with JPS listing multiple processes:
sudo su hduser
/usr/local/hadoop/sbin/start-dfs.sh
/usr/local/hadoop/sbin/start-yarn.sh